The Stark Effect in Hydrogen

In these notes we consider the Stark effect in hydrogen and alkali atoms as a physically interesting example of bound state perturbation theory. The Stark effect concerns the behavior of atoms in external electric fields. We choose hydrogen and alkali atoms because they are single-electron atoms (in the case of alkalis, this is a model). We particularly emphasize the role that symmetry principles play in the analysis of the Stark effect, and the physical ramifications. The first observations of the splitting of spectral lines by electric fields were made by Stark in 1913, for which he was awared the Nobel prize in 1919. Stark was an early supporter of Einstein’s relativity theory, as well as Einstein’s ideas about photons, about which most physicists of the time were very skeptical. After the Nazis came to power, however, he obtained a high position in the scientific establishment and, along with fellow Nobel laureate Philipp Lenard, promoted the notion that “Jewish physics,” which meant especially the theory of relativity, was degenerate and false. He also attacked Heisenberg, who defended both Einstein and relativity. After World War II, he was sentenced to four years in prison by a denazification court. Today Stark is remembered probably more for his racist and nationalistic political views than for his science.